Dennis,
I looked back in time to find your previous input on
the static…
On Feb 15
“Someone asked about my static RPM.
Today I checked - with engine just warm enough to open the throttle fully, I
got 5870 RPM with my new intake. With the engine completley warmed up I
got 5700 RPM. This demonstrates what Lynn Hanover has stated several
times - more air/fuel enter the combustion chamber at lower oil temps!
I believe with my original intake I only got about 5300 RPM static.”
I have a very similar setup to your original intake
and exhaust. I am not thru trying to tune the engine as yet. I have
a 76 X 88 Performance Props wooden propeller (like Ed and Tracy before they cut
them down to 74”). So far, my best static rpm has been 5500. I
suspect that I will have to change to your new intake to get much better, but
we will see after I can complete the tuning. (you don’t happen to
have one of those new intakes left over that you could send me, do you??
:>))
When you say you do better than your neighbor’s
Lyc, what do you mean? Better climb, better top end, better fuel, all of
the above??
I have been wondering about the static thrust that we
are generating with these planes. Has anyone tried to measure the static
thrust? Would someone try measuring it?
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Dennis Haverlah
Sent: Sunday, March 28, 2010 12:35
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: More
Renesis Flight Data
Chris,
Your static is very low compared to mine! My static is in the range of
5800 to 5850 rpm IIRC. I'll confirm static rpm soon. Does the
engine run smoothly at max rpm? I didn't know your engine was a 4 port
Renesis - I thought it was an earlier RX-7 unit.
A question was asked about my exhaust system and Hp.
I do slightly better than my neighbor's 180 hp. Lyc, powered RV-7A. He
and I will try to make some more comparisons this spring. I believe mine
is in the area of ~190 Hp. but it is only a guess. This is one reason I
wanted to post performance numbers so we can compare similar and different
systems.
My exhaust uses the Renesis exhaust manifold. The exhaust is pointed
forward toward the prop. To reverse the flow, I used a 4" dia.
stainless tube mounted horizontally and parallel to the prop. The tube
acts as a swirl tube - the flow enters parallel to the inboard end and exits
parallel to the outboard end of the swirl tube and the exhaust is toward the
rear of the aircraft. The exhaust than enters a Hushpower II Resonator
and than out and down to the rear. The resonator is shorter than the normal
Hushpower II muffler. All my exhaust system is inside the cowl. I
used some stainless and some aluminum for heat shields. With 230 hours of
total run time I have not had any problems.
See attached picture and the article in the current issue of Van's Rvaitor.
When I built the exhaust system "Swirl Mufflers" were the "in
thing" on the list. Also, I had trouble finding 180 deg. stainless
tubing with a sharp enough bend radius to fit in the space available in the
cowl. If I were building it now I'd use a 180 bend stainless tube instead
of the swirl tube. Probably would make a little more noise and Hp!
Dennis Haverlah
Chris and Terria wrote:
Dennis,
What is
the max static RPM you can get? There are two of us with the same
Renesis, RD1-C and Catto 76X88 and the best we get is 4750. Does that
match what you get?
Chris